Singapore and South Korea have just reported confirmed or suspected cases of monkeypox, according to the health authorities of the two countries, as the viral disease continues to spread across the world.

Singapore's health ministry said late on Tuesday that the country had confirmed an imported case of monkeypox, the first such case reported in Southeast Asia during this year's outbreak of the viral disease.

The patient, who tested positive on June 20, is a 42-year-old British man who works as a flight attendant and had flown in and out of Singapore around mid-June, the ministry said in a statement.

He is in stable condition in a ward at the National Centre for Infectious Diseases in Singapore, the ministry said.

Thirteen close contacts of the man were identified as of Tuesday, and all will be placed under quarantine for 21 days since their last contact with him, the statement added.

Contact tracing is ongoing for affected flights and for the duration of the man's stay in Singapore.

The last monkeypox case detected in the Southeast Asian city-state was three years ago. 

South Korea on Wednesday said the first two suspected cases of monkeypox have been reported in the country, adding that diagnostic tests were being conducted and health authorities will hold a briefing once the tests were completed.

One of the people with suspected monkeypox, a foreign national who reportedly showed potential symptoms since Sunday, entered the country on Monday and is currently under treatment in an isolation bed at a hospital in the city of Busan, some 300 km southeast of the capital Seoul.

The other, a Korean citizen who showed symptoms while entering the country from Germany on Tuesday afternoon, has been admitted to Incheon Medical Center.

"Diagnostic tests and epidemiological investigations on the monkeypox are being conducted and the health authority will swiftly hold a briefing to announce measures and response plans once the results are out," the Korea Disease Control and Prevention Agency (KDCA) said in a statement. 

(With input from Reuters)